• Juan Castillo's avatar
    Add optional platform error handler API · 40fc6cd1
    Juan Castillo authored
    This patch adds an optional API to the platform port:
    
        void plat_error_handler(int err) __dead2;
    
    The platform error handler is called when there is a specific error
    condition after which Trusted Firmware cannot continue. While panic()
    simply prints the crash report (if enabled) and spins, the platform
    error handler can be used to hand control over to the platform port
    so it can perform specific bookeeping or post-error actions (for
    example, reset the system). This function must not return.
    
    The parameter indicates the type of error using standard codes from
    errno.h. Possible errors reported by the generic code are:
    
        -EAUTH  : a certificate or image could not be authenticated
                  (when Trusted Board Boot is enabled)
        -ENOENT : the requested image or certificate could not be found
                  or an IO error was detected
        -ENOMEM : resources exhausted. Trusted Firmware does not use
                  dynamic memory, so this error is usually an indication
                  of an incorrect array size
    
    A default weak implementation of this function has been provided.
    It simply implements an infinite loop.
    
    Change-Id: Iffaf9eee82d037da6caa43b3aed51df555e597a3
    40fc6cd1
bl2_main.c 8.07 KB
/*
 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch.h>
#include <arch_helpers.h>
#include <assert.h>
#include <auth_mod.h>
#include <bl_common.h>
#include <debug.h>
#include <errno.h>
#include <platform.h>
#include <platform_def.h>
#include <stdint.h>
#include "bl2_private.h"

/*******************************************************************************
 * Load the BL3-0 image if there's one.
 * If a platform does not want to attempt to load BL3-0 image it must leave
 * BL30_BASE undefined.
 * Return 0 on success or if there's no BL3-0 image to load, a negative error
 * code otherwise.
 ******************************************************************************/
static int load_bl30(void)
{
	int e = 0;
#ifdef BL30_BASE
	meminfo_t bl30_mem_info;
	image_info_t bl30_image_info;

	/*
	 * It is up to the platform to specify where BL3-0 should be loaded if
	 * it exists. It could create space in the secure sram or point to a
	 * completely different memory.
	 *
	 * The entry point information is not relevant in this case as the AP
	 * won't execute the BL3-0 image.
	 */
	INFO("BL2: Loading BL3-0\n");
	bl2_plat_get_bl30_meminfo(&bl30_mem_info);
	bl30_image_info.h.version = VERSION_1;
	e = load_auth_image(&bl30_mem_info,
			    BL30_IMAGE_ID,
			    BL30_BASE,
			    &bl30_image_info,
			    NULL);

	if (e == 0) {
		/* The subsequent handling of BL3-0 is platform specific */
		e = bl2_plat_handle_bl30(&bl30_image_info);
		if (e) {
			ERROR("Failure in platform-specific handling of BL3-0 image.\n");
		}
	}
#endif /* BL30_BASE */

	return e;
}

/*******************************************************************************
 * Load the BL3-1 image.
 * The bl2_to_bl31_params and bl31_ep_info params will be updated with the
 * relevant BL3-1 information.
 * Return 0 on success, a negative error code otherwise.
 ******************************************************************************/
static int load_bl31(bl31_params_t *bl2_to_bl31_params,
		     entry_point_info_t *bl31_ep_info)
{
	meminfo_t *bl2_tzram_layout;
	int e;

	INFO("BL2: Loading BL3-1\n");
	assert(bl2_to_bl31_params != NULL);
	assert(bl31_ep_info != NULL);

	/* Find out how much free trusted ram remains after BL2 load */
	bl2_tzram_layout = bl2_plat_sec_mem_layout();

	/* Set the X0 parameter to BL3-1 */
	bl31_ep_info->args.arg0 = (unsigned long)bl2_to_bl31_params;

	/* Load the BL3-1 image */
	e = load_auth_image(bl2_tzram_layout,
			    BL31_IMAGE_ID,
			    BL31_BASE,
			    bl2_to_bl31_params->bl31_image_info,
			    bl31_ep_info);

	if (e == 0) {
		bl2_plat_set_bl31_ep_info(bl2_to_bl31_params->bl31_image_info,
					  bl31_ep_info);
	}

	return e;
}

/*******************************************************************************
 * Load the BL3-2 image if there's one.
 * The bl2_to_bl31_params param will be updated with the relevant BL3-2
 * information.
 * If a platform does not want to attempt to load BL3-2 image it must leave
 * BL32_BASE undefined.
 * Return 0 on success or if there's no BL3-2 image to load, a negative error
 * code otherwise.
 ******************************************************************************/
static int load_bl32(bl31_params_t *bl2_to_bl31_params)
{
	int e = 0;
#ifdef BL32_BASE
	meminfo_t bl32_mem_info;

	INFO("BL2: Loading BL3-2\n");
	assert(bl2_to_bl31_params != NULL);

	/*
	 * It is up to the platform to specify where BL3-2 should be loaded if
	 * it exists. It could create space in the secure sram or point to a
	 * completely different memory.
	 */
	bl2_plat_get_bl32_meminfo(&bl32_mem_info);
	e = load_auth_image(&bl32_mem_info,
			    BL32_IMAGE_ID,
			    BL32_BASE,
			    bl2_to_bl31_params->bl32_image_info,
			    bl2_to_bl31_params->bl32_ep_info);

	if (e == 0) {
		bl2_plat_set_bl32_ep_info(
			bl2_to_bl31_params->bl32_image_info,
			bl2_to_bl31_params->bl32_ep_info);
	}
#endif /* BL32_BASE */

	return e;
}

/*******************************************************************************
 * Load the BL3-3 image.
 * The bl2_to_bl31_params param will be updated with the relevant BL3-3
 * information.
 * Return 0 on success, a negative error code otherwise.
 ******************************************************************************/
static int load_bl33(bl31_params_t *bl2_to_bl31_params)
{
	meminfo_t bl33_mem_info;
	int e;

	INFO("BL2: Loading BL3-3\n");
	assert(bl2_to_bl31_params != NULL);

	bl2_plat_get_bl33_meminfo(&bl33_mem_info);

	/* Load the BL3-3 image in non-secure memory provided by the platform */
	e = load_auth_image(&bl33_mem_info,
			    BL33_IMAGE_ID,
			    plat_get_ns_image_entrypoint(),
			    bl2_to_bl31_params->bl33_image_info,
			    bl2_to_bl31_params->bl33_ep_info);

	if (e == 0) {
		bl2_plat_set_bl33_ep_info(bl2_to_bl31_params->bl33_image_info,
					  bl2_to_bl31_params->bl33_ep_info);
	}

	return e;
}

/*******************************************************************************
 * The only thing to do in BL2 is to load further images and pass control to
 * BL3-1. The memory occupied by BL2 will be reclaimed by BL3-x stages. BL2 runs
 * entirely in S-EL1.
 ******************************************************************************/
void bl2_main(void)
{
	bl31_params_t *bl2_to_bl31_params;
	entry_point_info_t *bl31_ep_info;
	int e;

	NOTICE("BL2: %s\n", version_string);
	NOTICE("BL2: %s\n", build_message);

	/* Perform remaining generic architectural setup in S-EL1 */
	bl2_arch_setup();

#if TRUSTED_BOARD_BOOT
	/* Initialize authentication module */
	auth_mod_init();
#endif /* TRUSTED_BOARD_BOOT */

	/*
	 * Load the subsequent bootloader images
	 */
	e = load_bl30();
	if (e) {
		ERROR("Failed to load BL3-0 (%i)\n", e);
		plat_error_handler(e);
	}

	/* Perform platform setup in BL2 after loading BL3-0 */
	bl2_platform_setup();

	/*
	 * Get a pointer to the memory the platform has set aside to pass
	 * information to BL3-1.
	 */
	bl2_to_bl31_params = bl2_plat_get_bl31_params();
	bl31_ep_info = bl2_plat_get_bl31_ep_info();

	e = load_bl31(bl2_to_bl31_params, bl31_ep_info);
	if (e) {
		ERROR("Failed to load BL3-1 (%i)\n", e);
		plat_error_handler(e);
	}

	e = load_bl32(bl2_to_bl31_params);
	if (e) {
		if (e == -EAUTH) {
			ERROR("Failed to authenticate BL3-2\n");
			plat_error_handler(e);
		} else {
			WARN("Failed to load BL3-2 (%i)\n", e);
		}
	}

	e = load_bl33(bl2_to_bl31_params);
	if (e) {
		ERROR("Failed to load BL3-3 (%i)\n", e);
		plat_error_handler(e);
	}

	/* Flush the params to be passed to memory */
	bl2_plat_flush_bl31_params();

	/*
	 * Run BL3-1 via an SMC to BL1. Information on how to pass control to
	 * the BL3-2 (if present) and BL3-3 software images will be passed to
	 * BL3-1 as an argument.
	 */
	smc(RUN_IMAGE, (unsigned long)bl31_ep_info, 0, 0, 0, 0, 0, 0);
}